/*
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html.
 *
 * This file is a derivative of code released by the University of
 * California under the terms listed below.
 *
 * Refinement Analysis Tools is Copyright (c) 2007 The Regents of the
 * University of California (Regents). Provided that this notice and
 * the following two paragraphs are included in any distribution of
 * Refinement Analysis Tools or its derivative work, Regents agrees
 * not to assert any of Regents' copyright rights in Refinement
 * Analysis Tools against recipient for recipient's reproduction,
 * preparation of derivative works, public display, public
 * performance, distribution or sublicensing of Refinement Analysis
 * Tools and derivative works, in source code and object code form.
 * This agreement not to assert does not confer, by implication,
 * estoppel, or otherwise any license or rights in any intellectual
 * property of Regents, including, but not limited to, any patents
 * of Regents or Regents' employees.
 *
 * IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT,
 * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
 * INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE
 * AND ITS DOCUMENTATION, EVEN IF REGENTS HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE AND FURTHER DISCLAIMS ANY STATUTORY
 * WARRANTY OF NON-INFRINGEMENT. THE SOFTWARE AND ACCOMPANYING
 * DOCUMENTATION, IF ANY, PROVIDED HEREUNDER IS PROVIDED "AS
 * IS". REGENTS HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
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 */
package com.ibm.wala.demandpa.alg;

import com.ibm.wala.demandpa.alg.statemachine.StateMachine;
import com.ibm.wala.demandpa.alg.statemachine.StateMachineFactory;
import com.ibm.wala.demandpa.flowgraph.AbstractFlowLabelVisitor;
import com.ibm.wala.demandpa.flowgraph.IFlowLabel;
import com.ibm.wala.demandpa.flowgraph.ParamBarLabel;
import com.ibm.wala.demandpa.flowgraph.ParamLabel;
import com.ibm.wala.demandpa.flowgraph.ReturnBarLabel;
import com.ibm.wala.demandpa.flowgraph.ReturnLabel;

/**
 * State machine that only allows intraprocedural paths. Mainly for testing purposes.
 *
 * @author Manu Sridharan
 */
public class IntraProcFilter implements StateMachine<IFlowLabel> {

  private static final State DUMMY = new State() {};

  @Override
  public State getStartState() {
    return DUMMY;
  }

  private static class InterprocFilterVisitor extends AbstractFlowLabelVisitor {
    @Override
    public void visitParamBar(ParamBarLabel label, Object dst) {
      interprocEdge = true;
    }

    @Override
    public void visitParam(ParamLabel label, Object dst) {
      interprocEdge = true;
    }

    @Override
    public void visitReturn(ReturnLabel label, Object dst) {
      interprocEdge = true;
    }

    @Override
    public void visitReturnBar(ReturnBarLabel label, Object dst) {
      interprocEdge = true;
    }

    boolean interprocEdge = false;
  }

  @Override
  public State transition(State prevState, IFlowLabel label) throws IllegalArgumentException {
    if (label == null) {
      throw new IllegalArgumentException("label == null");
    }
    // filter out all interprocedural edges
    InterprocFilterVisitor v = new InterprocFilterVisitor();
    label.visit(v, null);
    return v.interprocEdge ? ERROR : DUMMY;
  }

  private IntraProcFilter() {}

  public static class Factory implements StateMachineFactory<IFlowLabel> {

    @Override
    public StateMachine<IFlowLabel> make() {
      return new IntraProcFilter();
    }
  }
}
